Problem: $\left(x - 8\right)\left(-6x + 10\right) = \ ?$
$= x \cdot \left(-6x + 10\right) - 8 \cdot \left(-6x + 10\right)$ $= \left( x \cdot -6x \right) + \left( x \cdot 10 \right) + \left( -8 \cdot -6x \right) + \left( -8 \cdot 10 \right)$ $= -6x^2 + \left( x \cdot 10 \right) + \left( -8 \cdot -6x \right) + \left( -8 \cdot 10 \right)$ $= -6x^2 + \left( 10x + 48x \right) + \left( -8 \cdot 10 \right)$ $= -6x^2 + 58x + \left( -8 \cdot 10 \right)$ $= -6x^2 + 58x - 80$